Why is it der Tessiner?

Tessiner ends in -er, and most nouns ending in -er are masculine: in a German dictionary, 86% of them take der.

All nouns ending in -er
Sense 1
der

Meaning

[1] inhabitants of the Swiss canton of Ticino

[1] Einwohner des schweizerischen Kantons Tessin

Examples

[1]

[1]

Declension

1 Singular Plural
Nominativ der Tessiner die Tessiner
Genitiv des Tessiners der Tessiner
Dativ dem Tessiner den Tessinern
Akkusativ den Tessiner die Tessiner

Pronunciation

Dictionary entries include material from Wiktionary. Wiktionary